It is currently known to attempt to avoid congestion/overload situations in mobile radio communications networks by employing various forms of network access control for the mobile communication user terminal devices, such as identified as User Equipment (UE), which are active under network coverage.
The proliferation of the number of UE devices in the form of so-called smart phones under network coverage, and which are generally retained in an “always on” state, greatly increases the probability of each such UE device remaining in an RRC_Connected mode. This disadvantageously serves to make access control less effective since such known control is only applicable to UE devices in RRC_Idle mode.
In the absence of any such effective access control, the network, once experiencing an overloaded/comgested state is highly likely to remain in such a state and, indeed with the proliferation of RRC_Connected mode smart phones, to become even more overloaded/congested.
Such an overload situation is further exasperated by users of UE devices who may feel their attempted network access is particularly important, for example for emergency purposes. Such users will repeatedly attempt to achieve their required network communication and thereby repeatedly attempt to send mobile originating traffic from their then RRC_Connected UE devices such that the network is forced to attempt to process the network access request related to that mobile originating traffic. Ultimately, the network reacts by discarding even emergency, and other high priority calls, which of course can prove particularly disadvantageous.
Indeed, it has been recognised that it would be advantageous for the network to control the behaviour of UE devices in connected mode in an attempt to prevent mobile originating signalling and/or data traffic, while any access barring mechanisms might be being applied to the UE devices when in idle mode. Such suggestions have arisen in 3GPP Technical Specification Group focussing on Service and System Aspects—SA1 (S1-131279).
Various attempts have been made to meet this requirement as discussed further below but these are still disadvantageously limited having regard to the problematic scenario outlined above with regard to network congestion and overload and the undesirable barring of emergency and high priority calls.